Looking Outside the "Cardiac" Box: Incidental Detection of a Metastatic Lung Tumor on Cardiac Position Emission Tomography/Computed Tomography

Incidental extracardiac findings are not uncommon in patients undergoing cardiac positron emission tomography/computed tomography (PET/CT) and some of these findings can have significant clinical impact. We report a case of a 74-year-old man who presented with dyspnea and left sided chest pain. 82-rubidium PET/CT imaging showed normal myocardial perfusion. Review of the low dose CT scan performed for attenuation correction purposes (CTAC) incidentally revealed a 4 cm mass in the left lung, which was histologically shown to be a squamous cell carcinoma. A subsequent staging CT showed chest wall metastases and rib destruction in the upper left thorax, which were outside the image reconstruction field of view of the CTAC. This report illustrates the importance of vigilant review of all acquired images by the PET/CT reader to look for extracardiac abnormalities that may explain symptoms in the absence of coronary artery disease. It also raises the question as to whether a larger field of CT image acquisition should be routinely performed to scan the entire chest during cardiac PET/CT imaging. However, the latter needs to be weighed against the increase in patient dose, which we estimated to be an additional 15%